Heat engine

ABSTRACT

A pollution-free heat engine using a working fluid containing ammonia, including first means for heating and pressurizing the working fluid to a level of temperature and pressure whereat chemical dissociation or cracking of the ammonia into nitrogen and hydrogen takes place. Second means is provided for burning at least a portion of said cracked hydrogen as fuel for supplying part of the heat required in said first means.

United States Patent 3,7727 Engdahl NW. 26, '73

[54] ENGINE FOREIGN PATENTS OR APPLICATIONS lnvenlorl gichard Engdahl,Danbury, 19,356 9/1934 Australia 60/36 onn. 1

[73] Assignee: Energy Research Corporation, Primary ExaminerMartin P.Schwadron Bethel, Conn. Assistant Examiner-Allen M. Ostrager Filed: g1971 Att0meyR1chard D. Mason et al.

[21] Appl. No.: 168,865 [57] ABSTRACT A pollution-free heat engine usinga working fluid CCIH. Containing ammonia, including first means forheating o o 6 I 6 a I l 6 6 6 l q 6 6 6 l a [58] Fleld of Search 123/1A; 60/36 37 perature and pressure whereat chemical dissociation orcracking of the ammonia into nitro en and hydro- 56 R r c t d g 1 eerences l 8 gen takes place. Second means is provided for burning UNITEDSTATES PATENTS at least a portion of said cracked hydrogen as fuel for2,648,317 8/1953 Mikulasek 123/1 A supplying part of the heat requiredin said first means. 2,988,430 6/1961 Homer 2,988,431 6/1961 Kresse eta1. 60/36 x 29 Claims, 3 Drawmg Flgmes STACK P=5000 PSIA T=1500F 3620.6% N2+4.4%H2 so 75 "/6 H2O (STEAM) 42 5s 460 r IIIIIIIIIJ 46b stars58 l 2ND 5 9 STAGE f 1 5 46 as V s 7 T GP v MEIPPS TEIE 62 \r KL 36a 486 8;, f 2+-2 84 73 $558 5? 64 i will 4 N 32 TANK v \es CONDENSERSOLUTION PUMP JD RESERVOIR I/VVE/VTOR' R/CHARD E. ENGDAHL A TTOR/VE rsPAIEN IEUnnv 20 I975 SHEET 1 CF 3 PATENTEUNuvw ma SHEET 3 BF 3 ATTORNEYSHEAT ENGINE The present invention is directed to a new and improved heatengine which utilizes a working fluid containing ammonia and, moreparticularly, the engine provides means whereby the working fluid iselevated in temperature and pressure to a level whereat cracking orchemical dissociation of the ammonia into nitrogen and hydrogen takesplace. At least a portion of the cracked hydrogen gas is burned tosupply heat for elevating the temperature and pressure of the workingfluid, and the nitrogen (being relatively inert) does not recombine intooxides of nitrogen which contribute to pollution.

It is therefore an object of the present invention to provide a new andimproved heat engine which is substantially pollution-free in terms ofoxides of carbon and nitrogen.

Another object of the present invention is to provide a new and improvedheat engine which utilizes a working fluid containing ammonia andprovides means for chemically dissociating or cracking the ammonia intonitrogen and hydrogen, at least some of the hydrogen being burned tosupply heat for the cracking process.

Another object of the present invention is to provide a new and improvedheat engine of the character described which approaches a cycle ofoperation similar to the ideal Rankine cycle, modified however by thefact that the working fluid undergoes chemical dissociation or cracking,and one of the cracked components is utilized as a fuel source for theengine.

Still another object of the present invention is to provide a new andimproved heat engine of the character described in which the crackedcomponent of nitrogen gas does not recombine with oxygen or hydrogen andcan be exhausted to the atmosphere without significant pollution effect.

Another object of the present invention is to provide a new and improvedheat engine of the character described tuilizing utilizing working fluidcontaining ammonia and water.

Another object of the present invention is to provide a new and improvedheat engine of the character described employing an internal combustionprocess and utilizing ammonia as a fuel. I

Another object of the present invention is to provide a new and improvedinternal combustion engine of the character described in the precedingparagraph which operates in a manner whereby the ammonia is chemicallydissociated and hydrogen gas therefrom is used as a source of fuel forthe engine.

The foregoing and other objects and advantages of the present inventionare accomplished in one of the illustrated embodiments herein comprisinga heat engine using a working fluid containing ammonia and provided withfirst means for heating and pressurizing the working fluid to atemperature and pressure level whereat chemical dissociation or crackingof the ammonia into nitrogen and hydrogen takes place. At least aportion of the cracked hydrogen is used as a fuel to provide heat forthe chemical dissociation or cracking of the ammonia into hydrogen andnitrogen. The engine includes an expander wherein the working fluidentering at elevated temperature and pressure is expanded to do usefulwork and the engine includes a condenser means for condensing theexpanded working fluid. A storage tank is provided for the nitrogen andhydrogen gas, and means is provided for supplying gas from the tank foruse as a fuel to supply heat for the cracking process.

For a better understanding of the invention, reference should be had tothe following detailed description taken in conjunction with thedrawings, in which:

FIG. 1 is a schematic diagram illustrating a heat engine in accordancewith the features of the present invention;

FIG. 2 is a schematic diagram of a modified form of heat engine inaccordance with the invention, using a different operating cycleincluding an internal combustion process; and

FIG. 3 is a schematic diagram of yet another modifled form of heatengine, in accordance with the present invention, using a stilldifferent operating cycle and ammonia as fuel.

Referring now, more particularly, to the drawings and the embodimentillustrated in FIG. 1, a heat engine 10 is therein shown which utilizesa working fluid of aqueous ammonia and is constructed in accordance withthe features of the present invention. Ammonia is supplied from a highpressure storage tank 12 through a storage tank pressure regulatingvalve 14, a check valve 16, and a conduit 18 into a reservoir 20 whichcontains a solution of approximately 25 percent ammonia and percentwater under a pressure of approximately 15 psia and a temperature ofapproximately F. Water for the solution in the reservoir 20 is suppliedfrom a separator tank 22 via a conduit 24 and a check valve 26. Aqueousammonia from the reservoir 20 in a three-to-one ratio of water toammonia is pumped through a conduit 28 by means of a high pressure pump30 to a boiler-reactor, indicated generally by the numeral 32. The pump30 increases the pressure of the aqueous ammonia working fluid toapproximately 5,000 psia and the temperature is raised to approximatelyF. in the pumping process.

The high pressure, aqueous ammonia working fluid enters theboiler-reactor 32 and flows through a heat transfer coil 34 comprising aplurality of turns with a relatively large surface area to provide goodheat transfer for elevating the temperature of the working fluid. Theboiler-reactor 32 includes an insulated outer shell or casing 36 and aburner 38 adjacent one end for supplying heat to the working fluid as itflows through the heat transfer coil 34. An opening 360 is providedadjacent the burner for supplying combustion air, and the products ofcombustion pass over and around the heat transfer coil 34 which ispreferably formed of a strong, heat resistant metal, such as inconel orstainless steel, capable of withstanding the extremely high pressuresand temperatures involved. The products of combustion from theboiler-reactor are passed out through an exhaust stack 40 at one end ofthe boiler-reactor housing 36.

As the working fluid flows through the heat transfer coil 34, thetemperature of the fluid is raised to approximately 1,500 F. and thepressure remains relatively constant at approximately 5,000 psia. Theelevation in temperature causes the water in the working fluid to flashinto superheated steam and, at the same time, the ammonia is chemicallydissociated or cracked into gaseous nitrogen and hydrogen.

The working fluid mixture of steam, ammonia, hydrogen, and nitrogenleaves the heat exchanger coil 34 through a conduit 42 and passesthrough a throttle control valve 44 or variable admission angle controlinto a multistage expander, generally indicated by the reference numeral46. The working fluid mixture in the conduit 42 contains approximately20.6 percent nitrogen gas by weight and 4.4 percent hydrogen gas byweight plus 75 percent water in the form of super-heated steam. Theexpander 46 is shown in schematic form only and may take variousphysical forms, such as a radial array of cylinders, a plurality ofcylinders in an inline or V-type array, or a vane-type rotary expander.The main requirement of the multistage expander is to provide a wideenough range of expansion to utilize the available energy contained inthe high pressure, high temperature working fluid entering the expanderthrough the conduit 42.

In the expander 46, one or more high pressure working cylinders 46a areprovided with reciprocal pistons therein which are connected viaconnecting rods 48 to a common crankshaft 50. Connecting rods 58 areprovided to connect one or more larger pistons which are slidable inlarger low pressure expansion cylinders 46b. The working fluid entersthe high pressure side of the expander through a valve 54 and passesfrom the high pressure stage through an intermediate conduit 56 andengine operated and timed to piston position valve 58 through a engineoperated and timed to piston position valve 60 into the low pressureexpanding cylinders 46b. Spent fluid exits the low pressure cylindersvia a conduit 62 and engine operated and timed to piston position valve64.

The incoming working fluid entering the multistage expander 46 issupplied at a pressure of approximately 5,000 psia and at a temperatureof approximately l,500 F. After expansion of the fluid in the high andlow pressure stages of the expander, the fluid flows out through theexhaust conduit 62 at a pressure of approximately 20 psia and atemperature of approximately 200 F. It will thus be seen that a largequantity of work output is obtained during the expansion of the workingfluid in the multistage expander 46 and this work is available at therotating shaft 150. The crankshaft of the expander may be used to drivethe high pressure pump 30, as indicated by the dotted lines in thedrawing, and thus the pump may serve as a metering pump for supplyingfluid to the system at the desired rate as measured by the work outputof the engine in the expander stage.

Even though the working fluid undergoes a large pressure and temperaturedrop as it passes through the expander 46, the nitrogen and hydrogengas, which has been dissociated or chemically cracked from the ammoniain the boiler-reactor 32, does not recombine and the gases are retainedin separated form.

The working fluid in the exhaust conduit 62 from the second stage of theexpander passes into a condenser, generally indicated at 66. In thecondenser 66, the working fluid passes through a plurality ofair-cooled, finned tubes 66a, and the temperature of the fluid isreduced to approximately 150 F. The condensed water, ammonia, and thenitrogen and hydrogen collect in the sump portion 66b of the condenserand are directed into the separator tank 22 through a conduit 68.Airflow is directed over the condenser tubes 66a by a fan 70 and the fanmay be driven by the output shaft of the work expander, as indicated bythe dotted lines in the drawing.

In the separator 22, the liquid settles to the bottom and the nitrogenand hydrogen gas fills the space above the upper level of liquid. Thegaseous nitrogen is relatively chemically inert and does not readilycombine with oxygen or recombine with the gaseous hydrogen to reformammonia. The collected gases pass through a conduit 72, check valve 73,and a throttling valve 74 into the burner 38 in the boiler-reactor 32,and the hydrogen gas is burned (forming water-vapor) for supplying heatto the working fluid passing through the heat exchange coil 34.

No significant oxides of nitrogen are produced in the burning processwithin the boiler-reactor 32 and the stack gases passing out the exhauststack 40 consist of water-vapor and gaseous nitrogen, with little, ifany, traceable quantities of oxides of nitrogen, carbon monoxide andcarbon dioxide.

In order to supply fuel for initially starting up the engine 10 or forlarger power increases, an immediately available supply of fuel isrequired. For this purpose some of the hydrogen and nitrogen gas fromthe conduit 72 is passed through a branch conduit 76 and check valve 78into a pump 80 which delivers the gas to a storage tank 82. The pressureof the gas in the tank 82 is maintained by a sensor 84 and this sensorelectrically controls the pump to operate when needed. Gas from the tankmay be supplied to the burner 38 when required, through a constantpressure regulator valve 86, a check valve 88, and branch conduit intothe conduit 72.

The heat engine 10 provides many advantages over present day engines andthe operating cycles thereof. The engine 10 has an inherent, highefficiency operating cycle which approaches the ideal Rankine cycle butelimiates the problem of freezing of the working fluid, because of theuse of aqueous ammonia rather than water alone. The upper temperature inthe cycle is limited only by the strength and temperature limits of thematerials used in the boiler-reactor 32 and in the other portions of thesystem which are exposed to the high temperature, high pressure workingfluid. In a pure steam engine, the composition of the working fluiditself limits the maximum pressures and temperatures, but in the engine10, using aqueous ammonia instead of water, higher maximum temperaturesand pressures are obtainable and higher efficiencies are achieved. Inaddition, the engine 10 burns the cracked hydrogen gas as a fuel, andthis fuel is supplied from the chemical cracking process in theboiler-reactor 32, where the gas is dissociated from the ammonia of theworking fluid. No oxides of carbon are produced or passed to theatmosphere through the stack. Because of the high temperature andpressures involved, the boiler-reactor, expander, condenser, andreservoir and separator can be of relatively small size, yet a highpower output can be produced. Moreover, the operating parameters ofpressure and temperature may be higher as noted, as the thermalefficiency of the engine approaches an ideal Rankine cycle and may reachapproximately 36 percent, which is considerably higher than theefficiency of internal combustion engines and steam engines presentlyavailable.

Referring now, more particularly, to FIG. 2, therein is illustrated amodified form of heat engine constructed in accordance with the featuresof the present invention and referred to generally by the referencenumeral 110. Ammonia is supplied to the engine from a pressure tank 112,a constant pressure regulator valve 114, a check valve 116, and aconduit 118 which leads into a reservoir 120. Water is introduced intothe reservoir 120 from a separator tank 122 via a conduit 124 and checkvalve 126. An aqueous ammonia solution is formed in the reservoir andthe pressure therein is maintained at approximately 40 psia with atemperature of approximately 70 F. The ammonia and water, about half andhalf by weight, comprises the working fluid and is drawn from thereservoir 120 through a conduit 128 by a fluid pump 130, which increasesthe pressure of the working fluid to approximately 5,000 psia at atemperature of approximately 125 F. The working fluid is then passedthrough a cylinder jacket cooling system 192 formed around one or morebanks of cylinders in an internal combustion engine, generally referredto by the reference numeral 194.

After passage through the cooling system 192 of the internal combustionengine, the working fluid is directed via a conduit 196 into a heatexchanger coil 134 in a boiler-reactor vessel, generally indicated as132. The working fluid entering the boiler-reactor is at a pressure ofapproximately 5,000 psia and a temperature of 150 F., and as it passesthrough the plurality of turns in the heat exchanger coil 134, thetemperature of the fluid is elevated until cracking or chemicaldissociation of the ammonia into hydrogen and nitrogen gas takes placeand the water is flashed into superheated steam. The chemicallydissociated working fluid (comprising steam, ammonia, nitrogen andhydrogen) is passed from the heat exchanger coil 134 in theboilerreactor 132 through a conduit 142 and throttle control valve 144or variable admission angle control into the first stage of a multistageexpander 146. As previously described in connection with the expander 46of the heat engine 10, the expander 146 may take on a variety ofphysical embodiments, and the illustration shown is by way of exampleonly. The first or high pressure stage of the expander may comprise oneor more high pressure cylinders 146a having reciprocating pistonstherein and connected by connecting rods 148 to a common crankshaft 150.A second, low pressure stage, comprising one or more cylinders 146bhaving pistons connected to the crankshaft 150 by connecting rods 152 isprovided for a final stage of expansion of the working fluid.

The boiler-reactor 132 is enclosed in an insulated outer jacket 136 andan inlet opening 136a is provided at one end for the entry of hot gasesfrom the exhaust manifold system 198 of the internal combustion engine194. These high temperature exhaust gases from the internal combustionengine 194 are utilized in the boiler-reactor 132 for elevating thetemperature of the working fluid toa level whereat cracking of theammonia into nitrogen and hydrogen gas and flashing of the water andsteam into superheated steam take place.

After the hot exhaust gases flow over and around the coils of the heatexchanger 134, they pass out through a stack 140 at the opposite end ofthe boiler-reactor vessel. The exhaust gases contain water and nitrogen,but have no carbon monoxide or carbon dioxide therein and little, ifany, oxides of nitrogen.

The working fluid at elevated pressure and temperature leaving the coil134 passes through the throttle valve 144 into the multistage expander146 and flows through a timed from piston position valve 154 into thefirst stage cylinders 146a. After high pressure expantion, the fluidpasses through a timed from piston position valve 158 via a conduit 156leading to the second stage cylinders 1461) of the expander. Theexpanded fluid passes from the expansion cylinders 146b via an exhaustconduit 162 and a timed from piston position valve 164 into a condenser166. After expansion, the working fluid, consisting of water plusnitrogen and hydrogen gas, is reduced in pressure to approximately 40psia and in temperature to approximately 300 F. as it enters thecondenser 166 for further cooling. The working fluid passes through theair-cooled, finned tubes 166a and airflow is supplied by a fan 170 whichpreferably may be driven by the crankshaft 150 (as indicated by thedotted lines on the diagram) of the multistage expander 146.

Cooling of the working fluid in the condenser 166 lowers the temperatureto approximately 200 F., and the liquid and gas collect in the lowersump 166b for passage via a conduit 168 into the separator vessel 122.In addition to the work output obtained from the expanding working fluidin the expander 146, the internal combustion engine 194 also provides anadditional source of power which is usable in a variety of differentapplications. The internal combustion engine 194 and the multistageexpander 146 may be part of a common engine block, and both sections maydeliver power to a common rotating crankshaft 150 (as shown by theconnected dotted lines). The shaft 150 also may drive the solution pump130, the fan 170, and a gas pump 180 used for filling the gas storagetank 182.

The condensed water collects in the bottom half of the separator vessel122 and the chemically dissociated or cracked out nitrogen and hydrogengases occupy the space above the level of the water. The gas flowsthrough a supply conduit 172 into a carburetor which is adapted toproportion outside air with the gas for delivery ofa combustible mixturethereof to the cylinders of the internal combustion engine 194 throughan intake manifold system indicated by the reference numeral 197. i

As previously described, the exhaust gases leaving the cylinders of theinternal combustion engine 194 are delivered via an exhaust manifoldsystem 198 into the inlet opening 136a in the boiler-reactor 132 forheating the working fluid to a superheated cracking temperature. Theinternal combustion engine portion 194 of the heat engine 110 thus usescracked hydrogen gas as a fuel, and this gas is supplied from thecracking or chemical dissociation process that takes place in theboiler-reactor. Burning of the hydrogen gas within the cylinders of theinternal combustion engine 194 produces nonpolluting products ofcombustion (namely, water). The nitrogen gas supplied with the hydrogenfrom the cracking process, along with the nitrogen in the outside airentering the carburetor 195, does not recombine with the oxygen orhydrogen in the combustion process in the engine 194 and the exhaustgases pass out the stack 140 without appreciable pollutants therein asthe nitrogen remains uncombined, and no oxides of carbon are present.

For initially starting the heat engine 110, a hydrogen and nitrogenstorage and supply tank 182 is provided and this tank is supplied fromthe separator to carburetor conduit 172 through a branch conduit 176, acheck valve 178, and a pump 180, which is controlled by a pressuresensor 184 in the tank. When needed, gas passes from the tank through aconstant pressure regulator valve 186 and a check valve 188 and a branchconduit 190 back into the supply conduit 172 to the carburetor 195.

It will thus be seen that the heat engine 110 provides additional powerby means of an internal combustion engine 194 and yet is pollution-freein that the exhaust gases passing through the stack I40 contain nooxides of carbon or nitrogen. It has been calculated that the heatengine 110, operated as described, witll produce a thermal efficiency of51.8 percent, which is considerably higher than available from presentday internal combustion engines.

The engines 10 and 110 operate on partially closed cycles in that aportion of the working fluid (namely, the water) is retained in a closedcycle and is used over and over again. A portion of the cracked orchemically dissociated gases of nitrogen and hydrogen available from theammonia are burned and pass out through the exhaust stack 140 into thestmosphere while some of this gas is maintained in the tank 182. Theheat engine 110 operates on a cycle similar to the Rankine cycle forsteam and, while the engine is in some instances like a steam ornoninternal combustion engine, an internal combustion engine process iscombined therein to provide a very high thermal efficiency. Both engines10 and 110 have the advantage of being substantially pollution-free interms of carbon oxides and oxides of nitrogen.

Referring now, more particularly, to FIG. 3, therein is illustratedanother embodiment of a heat engine constructed in accordance with thefeatures of the present invention and referred to generally by thereference numeral 210. In the heat engine 210, ammonia is supplied froma high pressure storage tank 212 through a storage tank pressureregulator valve 214, a check valve 216, and a conduit 218 to the inletside of a high pressure pump 230. The pump 230 increases the pressure ofthe working fluid, which consists only of ammonia, from approximately 40psia at the output of the regulator valve 240 to approximately 500 psia,and the temperature is increased from ambient temperature of 70 toapproximately 150, after passage through the pump. The pump supplieshigh pressure working fluid via a conduit 228 to a cooling jacket 292 ofan internal combustion engine 294 having a rotating crankshaft 250 and aplurality of pistons therein connected to the shaft by connecting rods,in the customary manner.

After passing through the cooling jacket 292, wherein the cylinder wallsof the engine are cooled, the working fluid, at a pressure ofapproximately 500 psia and a temperature of approximately 200 F., passesthrough a conduit 296 into a boiler-reactor vessel 232 and flows througha heat exchange coil 234 therein. The boiler-reactor vessel includes aninsulating housing 236 and includes an exhaust stack 240 for exhaustinggas to the atmosphere. As the working fluid passes through the heatexchanger coil 234, the temperature and pressure are elevated to a levelwhereat cracking of the ammonia or chemical dissociation of the ammoniainto nitrogen and hydrogen gas takes place. The high temperature workingfluid leaving the heat exchager coil 234 is directed through a divideror teefitting 235 and flows to a storage tank 282 via a conduit 272, acheck valve 178 and a fluid pump 280, or to a carburetor 295 of aninternal combustion engine 294. A hydrogen and nitrogen gas storage tank282 provides a standby source of fuel for the engine 210, and the gas isdrawn from the tank when needed through a constant pressure regulatorvalve 286, a check valve 288, and a conduit 290 into a carburetor 295.After the engine is initially started and in operation, most of the fuelin the form of gaseous hydrogen is supplied directly to the carburetorthrough the line 242 from the tee-fitting 235.

In the carburetor, hydrogen fuel is mixed with air and the combustiblemixture is introduced into the cylinders of the internal combustionengine 294 through an intake manifold system 297. The exhaust productsof combustion from the engine contain mainly water and gaseous nitrogen,and these gases are delivered via an exhaust manifold system 298 intothe boiler-reactor 232 through an inlet opening 236a for heating theworking fluid in the coil 234. The high temperature products ofcombustion from the engine 294 heat the working fluid passing throughthe heat exchanger coil 234 to a level sufficient to crack the ammoniainto nitrogen and hydrogen.

The heat engine 210 of the present invention uses ammonia as a fuel andin the boiler-reactor 232, the ammonia is cracked or chemicallydissociated into gaseous nitrogen and hydrogen. The hydrogen provides asource of fuel for starting and running the engine, which issubstantially pollution-free because the gases passing out the stack 240do not contain oxides of nitrogen or carbon, but merely water andgaseous nitrogen.

While there have been illustrated and described several embodiments ofthe present invention, it will be appreciated that numerous changes andmodifications will occur to those skilled in the art, and it is intendedin the appended claims to cover all those changes and modificationswhich fall within the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. In combination a heat engine using a working fluid containing ammoniaand water, first means for elevating the temperature and pressure ofsaid fluid to a level sufficient to vaporize the fluid whereat chemicaldissociation of said ammonia into nitrogen and hydrogen gas takes place,second means for separating said nitrogen and hydrogen gas from saidwater, and third means for burning at least a portion of said separateddissociated hydrogen gas to supply part of the heat required by saidfirst means.

2. A heat engine as set forth in claim 1 including work output means forexpanding said vaporous working fluid after it has reached said elevatedlevel of pressure and temperature in said first means.

3. The heat engine of claim 2 wherein said second means includes meansfor cooling said working fluid to condense said water into liquid formafter expansion in said work output means to separate the water fromsaid dissociated nitrogen and hydrogen gas.

4. The heat engine of claim 1 wherein said first means includes pumpmeans for elevating the pressure of said fluid and boiler-reactor meansfor elevating the temperature of said fluid to said level sufficient tovaporize said fluid and produce chemical dissociation of said ammoniatherein.

5. The heat engine of claim 4 including means for driving said pumpmeans from said work output means.

6. The heat engine of claim 4 wherein said third means comprisesinternal combustion engine means.

7. The heat engine of claim 6 wherein said boilerreactor means is heatedfrom exhaust gases of said internal combustion engine means.

8. The heat engine of claim 6 including work output means for expandingsaid working fluid after said fluid is in vapor phase at said elevatedpressure and temperature level in said first means.

9. The heat engine of claim 8 including condenser means for cooling saidworking fluid after expansion in said work output means to condense saidwater into liquid form without condensing said nitrogen and hydrogeninto liquid form.

10. A heat engine using a working fluid which includes ammonia and watercomprising pump means for pressurizing said fluid, heating means forelevating the temperature of said pressurized fluid to a levelsufficient to vaporize the fluid whereat dissociation of said ammoniainto nitrogen and hydrogen gas takes place, expander means forconverting energy from said vaporized fluid into mechanical work,condenser means for cooling said expanded fluid to condense the waterthereof into liquid form, and separate the same from said dissociatedgases and means supplying said separated dissociated gases as fuel forsaid heatingimeans.

1]. The heat engine of claim 10 including internal combustion enginemeans, carburetor means for supplying a combustible mixture to saidengine means, means supplying said dissociated gases to said carburetormeans.

12. The heat engine of claim 10 including an exhaust system for saidinternal combustion engine means supplying heated exhaust gasestherefrom to said heating means.

13. The heat engine of claim 12 including heat exchange means forcooling said internal combustion engine means and thereby preheatingsaid working fluid prior to entry of said fluid into said heating means.

14. A heat engine using a mixture of ammonia and water as a workingfluid comprising, fluid supply means, pump means for elevating thepressure of said fluid, heating means for elevating the temperature ofammonia of said fluid received from said pump means to a levelsufficient to vaporize the same whereat chemical dissociation of saidammonia into nitrogen and hydrogen gas takes place, means for separatingsaid dissociated gases from said water, internal combustion engine meansincluding carburetor means for using said dissociated gas as a fuel andexhaust means for supplying heat for said heating means.

15. The heat engine of claim 14 including storage tank means forcontaining said gas not used in said carburetor means of said internalcombustion engine.

16. A heat engine utilizing a working fluid comprising a mixture ofwater and ammonia, comprising means for injecting makeup ammonia intosaid water at a first stage, pump means for elevating the pressure ofsaid fluid from said first stage to a higher level, boiler means forelevating the temperature of said fluid received from said pump means toa higher level sufficient to vaporize said fluid and chemicallydissociate the nitrogen and hydrogen of said ammonia, expander means forextracting work from fluid received from said boiler means as the fluidis expanded to a lower pressure, condenser means for cooling fluidreceived from said expander means to condense the water of said fluidinto liquid form while leaving said nitrogen and hydrogen in gaseousform, and separator means for removing said gaeous nitrogen and hydrogenprior to return of said water to said first stage.

17. The heat engine of claim 16 wherein said boiler means includesburner means for heating said fluid, said burner means including meansfor oxidizing at least a portion of said hydrogen gas removed from saidworking fluid by said separator means.

18. The heat engine of claim 17 wherein said separator means includes apressure tank for receiving and holding said gas removed from said fluidfor supply to said burner means.

19. A method of doing work comprising the steps of forming a workingfluid of ammonia and water, elevating the temperature and pressure ofsaid fluid to vaporize the same and chemically dissociate the ammoniainto hydrogen and nitrogen, expanding said fluid to do work whilelowering the pressure thereof, cooling said expanded fluid to condensethe water into liquid form while said nitrogen and hydrogen remain ingaseous form, removing at least a portion of the gaseous hydrogen fromsaid fluid and oxidizing the same to supply heat for elevating thetemperature of said fluid to vaporzie the same.

20. The method of claim 19 including the steps of storing said hydrogenand nitrogen gases separated from said working fluid and metering at acontrolled rate the flow of said stored gases to be oxidized to therebycontrol the heat supplied for elevating the temperature of said fluid.

21. The method of claim 19 including the step of metering said vaporizedfluid at a controlled flow rate for expansion to thereby control therate of work output therefrom.

22. The method of claim 19 wherein said forming step comprisesintermixing of ammonia and liquid water to a selected concentration.

23. A heat engine operable with a working fluid having at least twocomponents which undergoes a chemical change during each cycle ofoperation through a circulating system, comprising boiler means forelevating the heat value of said fluid to vaporize the same and causechemical dissociation of at least one component therein into acombustible gas and another gas, expander means receiving said fluidfrom said boiler means for extracting work therefrom during expansionthereof from high to low pressure, condenser means for cooling saidfluid to condense another component of said fluid into liquid form andretain said gases in vapor form, separator means for removing said gasesfrom said fluid for combustion of said combustible gas, and fluid makeupmeans for supplying said one component to said fluid to make up for theamount lost by chemical dissociation of the same prior to recirculationof said fluid through said boiler means.

24. The heat engine of claim 23 wherein said boiler means includes aburner for oxidizing said combustible gas for providing heat energy tovaporize said fluid and cause said chemical dissociation.

25. The heat engine of claim 24 including storage means for holding saidgases separated from said fluid by said separator means and means forsupplying said gases at a controlled rate to said burner means forcombustion.

26. The heat engine of claim 23 including pump means receiving saidfluid from said fluid makeup means for elevating the pressure of saidfluid delivered to said boiler means.

controlling the work output of said engine.

29. The heat engine of claim 9, wherein said noncondensed hydrogen fromsaid cooling means is mixed with oxygen from the air and burned toprovide at least a portion of the heat for said boiler-reactor means.

2. A heat engine as set forth in claim 1 including work output means forexpanding said vaporous working fluid after it has reached said elevatedlevel of pressure and temperature in said first means.
 3. The heatengine of claim 2 wherein said second means includes means for coolingsaid working fluid to condense said water into liquid form afterexpansion in said work output means to sepArate the water from saiddissociated nitrogen and hydrogen gas.
 4. The heat engine of claim 1wherein said first means includes pump means for elevating the pressureof said fluid and boiler-reactor means for elevating the temperature ofsaid fluid to said level sufficient to vaporize said fluid and producechemical dissociation of said ammonia therein.
 5. The heat engine ofclaim 4 including means for driving said pump means from said workoutput means.
 6. The heat engine of claim 4 wherein said third meanscomprises internal combustion engine means.
 7. The heat engine of claim6 wherein said boiler-reactor means is heated from exhaust gases of saidinternal combustion engine means.
 8. The heat engine of claim 6including work output means for expanding said working fluid after saidfluid is in vapor phase at said elevated pressure and temperature levelin said first means.
 9. The heat engine of claim 8 including condensermeans for cooling said working fluid after expansion in said work outputmeans to condense said water into liquid form without condensing saidnitrogen and hydrogen into liquid form.
 10. A heat engine using aworking fluid which includes ammonia and water comprising pump means forpressurizing said fluid, heating means for elevating the temperature ofsaid pressurized fluid to a level sufficient to vaporize the fluidwhereat dissociation of said ammonia into nitrogen and hydrogen gastakes place, expander means for converting energy from said vaporizedfluid into mechanical work, condenser means for cooling said expandedfluid to condense the water thereof into liquid form, and separate thesame from said dissociated gases and means supplying said separateddissociated gases as fuel for said heating means.
 11. The heat engine ofclaim 10 including internal combustion engine means, carburetor meansfor supplying a combustible mixture to said engine means, meanssupplying said dissociated gases to said carburetor means.
 12. The heatengine of claim 10 including an exhaust system for said internalcombustion engine means supplying heated exhaust gases therefrom to saidheating means.
 13. The heat engine of claim 12 including heat exchangemeans for cooling said internal combustion engine means and therebypreheating said working fluid prior to entry of said fluid into saidheating means.
 14. A heat engine using a mixture of ammonia and water asa working fluid comprising, fluid supply means, pump means for elevatingthe pressure of said fluid, heating means for elevating the temperatureof ammonia of said fluid received from said pump means to a levelsufficient to vaporize the same whereat chemical dissociation of saidammonia into nitrogen and hydrogen gas takes place, means for separatingsaid dissociated gases from said water, internal combustion engine meansincluding carburetor means for using said dissociated gas as a fuel andexhaust means for supplying heat for said heating means.
 15. The heatengine of claim 14 including storage tank means for containing said gasnot used in said carburetor means of said internal combustion engine.16. A heat engine utilizing a working fluid comprising a mixture ofwater and ammonia, comprising means for injecting makeup ammonia intosaid water at a first stage, pump means for elevating the pressure ofsaid fluid from said first stage to a higher level, boiler means forelevating the temperature of said fluid received from said pump means toa higher level sufficient to vaporize said fluid and chemicallydissociate the nitrogen and hydrogen of said ammonia, expander means forextracting work from fluid received from said boiler means as the fluidis expanded to a lower pressure, condenser means for cooling fluidreceived from said expander means to condense the water of said fluidinto liquid form while leaving said nitrogen and hydrogen in gaseousform, and separator means for removing said gaeous nitrogen and hydrogenprior to return of said water to said firsT stage.
 17. The heat engineof claim 16 wherein said boiler means includes burner means for heatingsaid fluid, said burner means including means for oxidizing at least aportion of said hydrogen gas removed from said working fluid by saidseparator means.
 18. The heat engine of claim 17 wherein said separatormeans includes a pressure tank for receiving and holding said gasremoved from said fluid for supply to said burner means.
 19. A method ofdoing work comprising the steps of forming a working fluid of ammoniaand water, elevating the temperature and pressure of said fluid tovaporize the same and chemically dissociate the ammonia into hydrogenand nitrogen, expanding said fluid to do work while lowering thepressure thereof, cooling said expanded fluid to condense the water intoliquid form while said nitrogen and hydrogen remain in gaseous form,removing at least a portion of the gaseous hydrogen from said fluid andoxidizing the same to supply heat for elevating the temperature of saidfluid to vaporzie the same.
 20. The method of claim 19 including thesteps of storing said hydrogen and nitrogen gases separated from saidworking fluid and metering at a controlled rate the flow of said storedgases to be oxidized to thereby control the heat supplied for elevatingthe temperature of said fluid.
 21. The method of claim 19 including thestep of metering said vaporized fluid at a controlled flow rate forexpansion to thereby control the rate of work output therefrom.
 22. Themethod of claim 19 wherein said forming step comprises intermixing ofammonia and liquid water to a selected concentration.
 23. A heat engineoperable with a working fluid having at least two components whichundergoes a chemical change during each cycle of operation through acirculating system, comprising boiler means for elevating the heat valueof said fluid to vaporize the same and cause chemical dissociation of atleast one component therein into a combustible gas and another gas,expander means receiving said fluid from said boiler means forextracting work therefrom during expansion thereof from high to lowpressure, condenser means for cooling said fluid to condense anothercomponent of said fluid into liquid form and retain said gases in vaporform, separator means for removing said gases from said fluid forcombustion of said combustible gas, and fluid makeup means for supplyingsaid one component to said fluid to make up for the amount lost bychemical dissociation of the same prior to recirculation of said fluidthrough said boiler means.
 24. The heat engine of claim 23 wherein saidboiler means includes a burner for oxidizing said combustible gas forproviding heat energy to vaporize said fluid and cause said chemicaldissociation.
 25. The heat engine of claim 24 including storage meansfor holding said gases separated from said fluid by said separator meansand means for supplying said gases at a controlled rate to said burnermeans for combustion.
 26. The heat engine of claim 23 including pumpmeans receiving said fluid from said fluid makeup means for elevatingthe pressure of said fluid delivered to said boiler means.
 27. The heatengine of claim 26 including drive means interconnecting said expandermeans and said pump means for driving the latter from the former. 28.The heat engine of claim 23 including throttle valve means forcontrolling the flow of vaporized fluid from said boiler means into saidexpander means for controlling the work output of said engine.
 29. Theheat engine of claim 9, wherein said noncondensed hydrogen from saidcooling means is mixed with oxygen from the air and burned to provide atleast a portion of the heat for said boiler-reactor means.